What sort of car do you want mate
A bigish saloon, if so then you should be able to pick up a nice vectra or Mondeo for about 3 to 4 grand.
If you want a hatch back – then i would agree with Rainnywainnybumpbumpyfrumikins and get an Astra or even a golf.
If you want something smaller then possible a fiesta.
If you want a small sports car, then you might just be able to afford a MX5 or even an MGF
Just some choices mate, they aint bad cars, it wouldn’t kill me to be seen in any of them, and i wouldn’t give bad advice :D